This DPD Series 3-phase voltage and frequency monitoring relay provides protection against phase reversal, phase loss and if the phase asymmetry, voltage or frequency measurements are not within the user-configured settings and/or thresholds. The DPD Series settings can easily be modified through an Android App via a smartphone/tablet or via a USB NFC reader/writer connected to a computer. Under and over threshold settings can be set, as well as hysteresis and time delays. They are uploaded into the DPD Series by means of its NFC configuration. Neither potentiometer settings nor DIP switches are used for the device set-up, and after it is set-up, it can be password protected, to ensure safety while in use.The main advantage of the DPD Series is its high versatility and multifunction design. The set-up can be changed at any time and can be replicated, and stored on as many devices as needed. The set-points are extremely precise as they are digital, and much more accurate than they would be with potentiometer settings.